The present invention relates to a method of transmitting a pulse code modulated (PCM) signal in a biphase code including a complete sequence of level changes and a sequence of level changes containing gaps. More particularly the present invention relates to such a method utilizing a novel synchronizing pattern for the transmitted signal.
At the 12th meeting of the 8-mm Video Conference, Audio Workgroup, on Mar. 28th, 1983, in Tokyo, Japan, a biphase signal synchronizing pattern comprising two mutually inverted bits each having a length of 1.5 clock pulse periods was proposed.
By definition, the maximum ratio of level change intervals in a biphase signal is fixed at 2:1. Increasing this ratio to 3:1 has a significant influence on the biphase spectrum. To compensate for this drawback, different equalizer circuits are required as well as a broader transmission channel. The above mentioned biphase signal is described in "Fairchild: The Interface Handbook, 1975, Page 4-18".